I've used Penetrol on older cars and parts of the GMC frame to protect from rust.
It's a paint conditioner and also sold to treat unpainted metal such as shovel blades and other tools.
I clean the frame and apply with a brush. It creeps into voids such as the sandwiched area of the GMC frame.
Dennis
> In the North Eastern parts of the USA, where they use road salt, waxing the
> frame is the least you should do. Some people make a point of using a
> pressure washer, followed up with a garden sprayer filled with used ATF,
> and spraying everything under there until it drips off like rain. There are
> commercial products with anti-corrosion properties made just for this task.
> I am all for anything you can do to keep the "tin worms" away from your
> frame, and anything else under there subject to corrosion from that salt.
> Several friends make an annual trek to the Bonneville Salt Flats with
> their racing machines. No matter what you do to clean up the undercarriage
> of those cars, when you work on them later, you always dig salt out of
> everywhere. It eats up everything.
> Jim Hupy
> Salem, Oregon
>
> On Sat, Jul 25, 2020, 1:12 PM Mike Hamm via Gmclist
>
> > How about a frame waxing?
> > --
> > 1977 Kingsley 455 as stock as it gets except lots of Ragusa parts
> >
> > _______________________________________________
> > GMCnet mailing list
> > Unsubscribe or Change List Options:
> >
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
> >
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
>
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
--
Dennis S
73 Painted Desert 230
Memphis TN Metro